Sound-reproducer.



, A. N. PIERMAN. SOUND REPRODUCER. APPLICATION msn MAR.22. 1906.

, 1, 1 48,61 9. Patented Aug. 3, 1915.

2 SHEETS-SHEET I.

` UNITED STATES PATENT v. OFFICE. ALEXANDER N. PIERMAN, F NEWARK, NEW JERSEY, ASSIGNOR T0 NEWJERSEY PATENT COMPANY, 0F WES'I` ORANGE, NEW JERSEY, A CORPORATION 0F NEW JERSEY.

SOUND-REPRODUCER.

Patented Aug. 3, 1915.

Application led March 22, 1906. Serial No. 307,324.

T0 all lwhom t may concern.'

Be it known thatI, ALEXANDER N. PIER- MAN, a citizen of the United States, residing at Newark, in the county of Essex and4 State of New Jersey, have'invented certain new and useful Improvements in Sound- Reproducers, of which the following. is a description.

My invention relates to sound reproducers of the type described and broadly claimed in my application filed November 24th, 1905,

Serial No. 288,837, wherein the sounds are produced by vibrations resulting from varyingthe extent of opening of ports situated in a sound chamber and adapted to permit the passage of a body of air or other'elastic fluid, the valve Ibeing elastic and operating by iexure, although the present invention may be applied to reproducers in which lthe valve is capable of pivotal or reciprocatory movement. In the operation of the apparatus disclosed in said application I have found that while very good reproduction of some phonograph records has been obtained, the reproduction of other records has been more or less imperfect, at least to persons whose hearing is sufficiently refined to enable them to detect the imperfection. Furthermore the said apparatus, while adapted to be operated by very low air pressure, such.

as that which will sustain a mercury column of about two and a half inches, will giveA favorable results only when the pressure within the exhaust tube which leads from the reproducer is maintained Vsubstantially constant. I have now discovered that it is possible to construct a reproducer of this .improvement will be hereinafter more fully set forth and claimed together with certain other improved details of construction. M v

invention also relates to improved means for producing a flow of through the reproducer, and to the mounting of the repro- Figure 1 1s a vertical section of a sound reproducer constructed -in accordance with my invention, the. sectional plane being indicated at 1-1, Fig. 3; Fig. 2 is a section on line 2 2 of Fig. 3; Fig. 3 is a section on line 3 3, of Fig. 1; Fig. 4 is a sectional detail of a modified connection between the valve and operating link. Fig. 5 is a plan view showing my invention applied to a phonograph of the Edison type.

In all the views correspondingparts are indicated by the same reference numerals.

The reproducer shown comprises a hollow body A composed of the cylinder 1, plate 5, and cap 6, the former being provided with 'depending and lateral annular anges 2 and 3 respectively which a're adapted to fit within the reproducer carrier arm b of a phonograph which forms a part of the travelmg carriage ai. The upper end of the cylinder 1` forms a seat 4: upon which the circular plate 5 of brass or other suitable material isclamped by the cap 6 threaded upon the cylinder 1 and having a shoulder7 which bears against the said plate 5 leaving preferably a low space or chamber 8 between .the

body of the cap 6 parallel thereto. A neck 9 having a cylindrical bore 10 whose diameter vis about the same as the length of the ports 40 of the plate 5 extends upward from the body of the cap 6 1s adapted to be connected with an amplifying horn or megaphone in any suitable manner as vby a section of rubber tubing; the space 8, bore 10 and horn form a resonating chamber or chambers leading from the atmosphere to -the ports 40. The plate 5 is substantially the same as that disclosed 1n the application referred to and may be onesixteenth of an inch in thiclmess and `provided with a series of rectangular slots 40 measuring one-half inch in length by three sixty-fourths of an inch in width at the valve seat, forming ports for the passagepf the air or other elastic fluid. In the device described in the said application the ,slotsI plate 5 and are formed with parallel walls, but improved results may be obtained b 'forming the slots so that the walls thereo converge in the direction of the iowof the elastic fluid as clearly shown in` Fig. 2. The cylinder 1 is apertured at 11 to receive the tubel 12 which is-` connected by Aa'iexible connec-4 tion, such as a rubber tube 41, with anyv suit# able apparatus for producing suction, for example-an air pump 42,.`th`e; flexible con' nection permitting thc-'Carrier arm b and body A kto be fed 'across the record bythe engagement of theusualfeed nut e with the feed screw 0,' while` a continuous flow of air is maintained through the reproducer. 'The Y extent of opening* of the plorts 40 is varied Y, by, any 'suitable valve, suc as the late13,

which may be of a hard, elastic an flexible.V

, material such as the- 'various'metals and` alloys, but which is preferably-of.-celluloid.. of the shape shown in the drawings and f measuring three-:fourths 'of' an inch square i by one th1rty-second of an inch inv thickness.

This` plate is seated upon and 'jcoverszthe ports 40 as shown, ybeing secured along one edgetothe plate 5 by screws 14, the o" po site or free edge being-*serrated to; orm tongues 15. A groove 16 is. formed trans-y. versely vof the plate 13 so asv to weaken the same alon the line of iiexure produced by, the operating link 17. A spring 18 is held at one end' b the middle screw 14 and presses at its ree end upon the plate' 13 at A or near its center. An adjusting screw19 passes through the intermediateportion of the spring-18 and plate 13 and is-threaded inthe plate 5,wherebyany desired degree' of pr'essureof thelspring 18 upon the plate 3 may be obtained and the spring 18 will bev held against lateral movement so that its free end will always bear upon the -medial line `of the valve 13. The retractile -force due to the resiliency of this spring and of the valve plate 13, .balances 0the downward v'force .due to the air pressure which will be produced upon the valve 13 by the action of the suctionv device applied 'to' the tube 12. The pressure of the spring increases as the plate is moved' downward which movement increases the flow of air so that a substan- ./tially `perfect balance is maintained all positions of Vthe plate 13, and byva rying the tensionof the spring 18 by the adjusting screw 19proper compensation may be'made for variations in the operating air pressure: and flexibility of the valve 13.. i The operatfv j ing' link 17 l1s connected atone 'endftojthe "11; valve 13 in any suitable. manner as by an eye 20 secured to said valve; .'Izhe connected at its other end to the-- lever21 4 which carries the reproducing '-styluszf22 24 carried-by a Hoa-ting weight'25 which 'I' pivoted at 26 to a block 2,7.threa-ded inv ther ange This weight moves Afreelyiiup down to permit the stylus 22 to follow `irregularities in lthe contour of the record sur# face a.

In order to lfacilitate the escape o fy air through the ports 40` of the plate 5, grooves -or recesses 28 are formed in the lower surface of said plate between and parallel to the said ports. These recesses 28 extend practically the entire length of the ports 40,

the ends of the said recesses extending beyond the limiting edge of the plate 13 so as to be in free communication with the equalsmall.

I have' `obtained favorable results with ports and 'valve of the dimensions'speciied and an air pressurev or suction capable of sustaining "two and one-half inches of mer- 'v cury by constructing the chamber 29 in the form ofa cylinder vwhose diameter is one and oneffourth inches and height one inch, but obviously the volume of this chambermay vary considerably, although it is of course desirable to make it as small as possible without impairing the quality a nd rangen `oflreproduction` of the apparatus. The increased size of the chamber- 29 not only equalizes the iow of air but eliminates objectionable vresonance whichsometimes oclmi curs with thedevice of my prior application as `a hissing sound like that of air escaping or exhausting through a small opening. The lower end ofthe chamber 29 is closed by'a plate 30 held against the annular houl! der 31 by a clamping ring 32 threaded within the flange 2. The plate 30 is provided with aj central aperture 33 through which the link 17 passes and this opening-is preferably of suk cient size to allow the link to operate freely,l the .opening 33 being closed by a small 4washer 34 of paper or other softmaterial which surrounds the link .17 and 'will be held against the plate 30 by atmospheric pressure.. By this means friction and vwear upon the link 17 'and leakage 'of air 'around the same are practically` eliminated. `In the modification of Fig. 4 the link 17 `is connected to the .valve plate 13 by aball and socket joint. The link 17 is preferably asmall wireE and the bal1f3'5v may lbe formed by fusingltheend thereof. i This l'ball-is held` .inf thevrsk'fa- 36 fomed in any suitable ma.. 120' ner'asby--ve'ementing tothe' plate .13a sock-` eted plate through apparatusamay be nsed, p but I prefer,v inI v n -f'jorder' tobbtain a uniform' flow, to use a tank The-lever v21 is pivoted at 23`to a'lu'g-or'lu 13 VAto. whichv the. tube A'41 is connected; an 'ex pf haust .pipe" .f14.leading fromiijsaid tank to.

iso

pump may be operated continuously during the reproduction of a sound record, by hand or a suitable motor, in which case the pump and the tank 43'1nay be of comparatively small dimensions. If desired, however, their size may be increased, and the pump used to produce a high degree of vacuum, (for instance one which will sustain 2G inches of mercury) in the tank 13, prior to the operation of the reproducer. A cylindrical tank measuring twelve inches in diameter by twelve inches in height when exhausted to this degree is of sufficient size to play one entire record of ordinary length.

The operation of the device is as follows: The body A being held in the traveling carrier arm of a phonograph with the stylus 22 in operative position lupon the phonogram or sound record a., suction is applied tothe tube 12 which produces a downward stress upon the plate 13 and yslightly opens ports 40. This stress is then balanced by the resiliency of the plate 13 and the upward pressure of the spring 18 so thatthe ports 40 remain slightly open, allowing the` passage of a stream of air. As the reproducer stylus 22 is moved upward by an elevation of the sound record groove, it draws the link 17 downwardly and causes the plate 13 to flex,-

thereby increasing the. extent of opening of the'ports 40 and allowing an increased flow of air therethrough. As the stylus Q2 passes over the elevation and descends into a depression, the elasticity of the plate 13 and of the spring `18 decreases the extent of opening of the ports 4Q thereby diminishing the flow of air. The varying of the extent of opening of the ports 40 is thus effected in exact accordance with the elevations and depressions of the sound record groove and the result is to produce sounds which are representative of said elevations and depressions, and which, as before stated, are of very perfeet quality and may be of great volume.

Having now described my invention, what I claim as new and 'desire to secure by Letters Patent is as follows:

1. In a sound reproducer, the combination of a hollow body, a port plate therein dividing the said hollow body into an equalizing chamber upon thel exit side of the said port plate and making up the greater portion of said hollow body, and a relatively small resonating chamber upon the opposite side of said port plate-a plate valve seated upon said port plate and upon the ports therein, means for producing a How of elastic fluid through the ports and means for'operating the plate valve to vary the extent of open ing of the ports, substantally as set forth.

2. In a sound reproducer, a hol-low body having a comparatively small resonating V chamberand an equalizing chamber having several times the volume of said resonating chamber, the said chambers communicating through ports, means for producing a flow of elastic fluid through said ports from said 'resonating chamber into said equalizing chamber, a valve seated upon said ports and means for ope 'ating said valve to vary the 70 extent of opening of the ports, substantially as set forth.

3. In a sound reproducer. the combination of a hollow body having ports, means 4for producing a1' flow o-f elastic fluid therethrough, a valve of elastic material sealed upon said ports, an equalizing chamber upon the exit side of said ports the volume of which is suflicient to prevent excessive variation in the operating fluid pressure, ,and means for Aliexing said valve to vary the extent of opening of said ports, substantially-as set forth.

4. In a sound reproducer, the combination of a hollow body having ports, and a celluloid plate secured at one edge and operating by flexure to vary the extent of opening of the ports, said plate being weakened along the line of flexurc, substantially as set forth. i

5. In asound reproducer, the-combina-A tion of a hollow body providedwith a port member having a set of ports therein, a plate for varying the extent of opening of said ports, recessesbetwcen adjacent ports, and means for flexing said plate, said recesses being so placed as to communicate with the ports only when the latter are 4 opened by said plate, substantially as set forth.

6. In a sound reproducer, the combination of a hollow body having slots therein and having grooves adjacent said slots` a plate seated on said slots and grooves, the grooves extending beyond the margin of said plate 105 and means for moving said plate, substantially as set forth.

7. In a fluid pressure sound reproducer, the combination of a hollow body having a resonance chamber and an equalizing cbam- 110 ber communicating through ports, said equalizing chamber being located on the exit side of said ports and having sufficient volume to prevent excessive variation in the operating Huid pressure, an apcrtured plate at the lower end of said body, a valve for varying the extent of opening of said ports, and means extending through said apertured plate for operating said valve, substantially as set forth.

8. In a fluid pressure sound reproducer, the combination of a hollow body having a resonance chamber and an equalizing chamber communicating through ports, said equalizing chamber being located on the 12,5 exit side of said ports and having sufficient volume to prevent excessivevariation in the operating fluid pressure, an apertured plate at the lower end of said body, a valve for varying the extent of opening -of said ports, 130

',ports, and means for operating said valve comprising a stylus, a pivoted fulcrum supi port, 'a lever pivoted thereon, and a link,

9. In' a sound reproducer, the combination of a hollow body having a set of ports,

a plate of elastic material seated upon said v ports, a spring pressing on said plate at or near its center, means for varying the pressure of said spring, and means forflexing said plate to vary the extent of opening of said`ports, substantially asset lforth.

10. In a sound reproducer, the combination of a hollow body having a set of ports, an elastic valve plate adapted to vary the extent of opening of said ports, a spring rigidly secured at one end and pressing at itsv free endagainst said valve plate -at or near/its center, andan adjusting screw pass- -ingthrough the intermediate portion of said.

sprlng, substantially as set forth.

1'1. In a sound reproducer, the combination of a hollow body having ports, a valve for varying the extent of opening of said said link'being connected to said valve by a universal joint, substantially as set forth.

12. In a sound reproducer, thecomb-ina-` tion of\a hollow body having ports, a valve -for varying the extent of opening of said ports, and means for'operating said valve comprising a stylus, a pivotally supportedl lever, and a link, said` linklbeing connected to said valve by al ball and socket joint, substantially as set forth.

` 13. In a sound reproducer, a hollow body having a resonating chamber, and an equal- M-izing chamberl communicating through ports, said equalizing chamber being located on the exit side of said portsand having volume to revent excessive variation in the operating uid pressure, a valve seated upon said ports, and means for operatingsaid ,valve to vary the extent of opening of said ports, substantially as set forth.

15. In a sound reproducer, the combination of al hollow body having ports, means for lproducing a How of elastic fluid therethrough, and av valve operating by flexure to vary the extent ofy opening of the ports, said valve being weakened along the line of ijlexure, substantially asset forth.

16. In a sound reproducer, the combina- \tion of a hollow body having ports, means for producing a iiow of elastic fluid therethrough, and a valve plate secured atone vedge and operating by flexurev to vary the extent of opening of the ports, said plate lbeing weakened along the line of lexure, substantially asset/forth.

17. Inaf/iuid pressure sound reproducer, a valve c omprising'a exible plate weak ened along its 'line of iexure by a groove, substantially as set forth.

This specification signed and witnessed this 21st day of March 1906.

ALEXANDER NJPIERMAN.

nWitnesses:

DELos HOLDEN, FRANK L. DYER'. 

